The present invention relates to surgical instruments, and in particular to a pin impactor and method of use thereof.
In surgical procedures, pins can be used to locate instrumentation on a bone. For example, during a knee replacement procedure, a femoral cutting block can be placed on the anterior, distal part of the femur adjacent the condyles and held in position by placing pins through a number of apertures in the cutting block and then driving the pins into the bone to prevent the cutting block from moving. Once the position of the cutting block is stabilised using the pins, the secondary fixing means, such as bone screws, can also be used to more securely attach the cutting block to the bone.
Typically at least two, or more, pins are used to fix the position of the instrument as otherwise the instrument can pivot about a single pin. An existing pin impactor can hold a single pin and is used twice to place two pins to fix a cutting block. However, this involves the surgeon using the pin impactor a first time to impact a first pin, and then the pin impactor being reloaded with a second pin, either by the surgeon or by somebody attending surgery, and then being used again to impact the second pin.
However, having to re-load the pin impactor introduces delays and difficulties into surgery. The re-loading of the pin impactor generally adds steps to the surgical procedure. If the surgeon, reloads the pin impactor, then he has to let go of the instrument being fixed, which may then move and therefore needs careful re-positioning before impacting the second pin.
If the pin impactor is reloaded by another person, then the surgeon can pass the pin impactor to them for reloading and then wait for it to be reloaded and passed back, again adding delays and more handling of sharps, as the pin tip is sharp. Alternatively, the surgeon can hold the empty pin impactor, while another person places a second pin in the impactor, but that can be a very fiddly manual activity as the pins can have small diameters and again requires the handling of sharps and so is potentially dangerous.
An alternative is simply to have multiple pin impactors each pre-loaded with a single pin, but that again introduces delays as each pin impactor is passed to and from the surgeon and also introduces more sharps and more sharps handling and also adds more instrumentation to an area already full of instruments.
It would therefore be beneficial to be able to more quickly, safely and easily allow more than one pin to be impacted by a surgeon.
The invention provides a multi-pin pin impactor which can be used by a surgeon to impact more than one pin, without requiring re-loading with pins.
BRIEF SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a multi-pin pin impactor, comprising: a body holdable by a user and manipulable by the user to re-position the pin impactor during use; a first pin holder attached to the body and including a first pin release mechanism effective to releasably retain a first pin within the first pin holder; a second pin holder attached to the body and including a second pin release mechanism effective to releasably retain a second pin within the second pin holder; and an impaction portion, by which a force can be applied to the multi-pin pin impactor to apply a driving force to one of the pins.
As the pin impactor can hold multiple pins in a releasable fashion, there is no need to re-load the pin impactor during use and so the number of steps is reduced, making surgery quicker, and also sharps handling is reduced making the risk of injury or glove damage less.
The pin impactor can include more than two pin holders. For example, the pin impactor can include three, four, five or more pin holders. Each pin holder can have the same or similar general construction. The pin impactor can comprise a further, or a plurality of further pin holders, each further pin holder including a pin release mechanism effective to releasably retain a pin within the pin holder. Hence, the pin impactor can be used to impact more than two pins, if needed to fix a piece of instrumentation or to fix more than one piece of instrumentation.
The pin impactor can be configured or can have a geometry to help reduce the chance of fouling of the pin impactor in use. The orientations of the first pin holder and the second pin holder can prevent fouling of the pin holder in use. The configuration or geometry of the pin impactor can be such that when the pin impactor is being used to impact a first pin, the second pin and any other pins do not foul against other instrumentation or the patient's bone.
The first pin holder can have a first longitudinal axis and the second pin holder can have a second longitudinal axis. The angle subtended by the first longitudinal axis and the second longitudinal axis can be between approximately 180° and 30°. The angle can be between approximately 180° and 120° The angle can be between approximately 120° and 45°. More preferably, the angle is between approximately 90° and 45°. The angle can be an obtuse angle or an acute angel, but preferably the angle is an acute angle. Most preferably the angle is approximately 60° or approximately 120°, the latter making the pin holder particularly suitable for use, for example, in minimally invasive procedures. The angle can be greater than approximately 30°. The angle between each adjacent pair of pin holders can be substantially the same.
The pin impactor can have a plurality of separate limbs. Each limb can provide either a pin holder or an impaction surface. An impaction surface can be provided at an opposite end of a limb providing an associated pin holder.
All of the pin holders can lie in a common plane. Hence, the pin impactor has a generally planar star shaped configuration.
All of the pin holders may not lie in a common plane. Hence, the pin impactor has a more three dimensional configuration. The longitudinal axes of the pin holders may lie on the vertices of a generally pyramidal shape.
The impaction portion can be a single impaction surface. The impaction surface can have different regions oriented in different directions so as to direct an impaction force toward a corresponding associated pin holder.
The impaction portion can include a separate impaction surface for each pin holder. The plane of each impaction surface can be generally perpendicular to the longitudinal axis of an associated pin holder.
The pin impactor can have a composite construction. The pin impactor can comprise a core of a first material. The pin impactor can comprise a coating disposed over at least a portion of the core. The coating can be of a second material which is different to the first material. The first material can be a load bearing material suitable to transmit an impaction force to a pin held by the impactor. The first material can be a rigid material.
The first material can be a plastic, and in particular a polymer. Suitable plastics for reusable pin holders include, for example PEEK, PAEK and PPSU. Suitable plastics for single use or disposable pin holders include, for example, PA66, POM, PC, ABS, PP, PARA. The plastic or polymer material can be fibre-reinforced, so as to provide extra rigidity, for example glass-fibre reinforced.
The first material can be a metal or alloy, such as stainless steel, titanium, aluminium, cobalt-chrome, brass or alloys including such metals. For single use or disposable pin holders, the metal can be steel, such as mild steel or carbon steel. The second material can provide a grip. The second material can be a resilient material such as a rubber or a plastic. The second material can be less rigid than the first material. The coating can be moulded over the core. The core can have a unitary construction or can be made from a plurality of core members. Each core member can have a generally similar construction.
Each pin release mechanism can include a friction fit part. The friction fit part can provide sufficient friction to prevent a pin falling out of the pin holder under the action of gravity, vibration or momentum of the pin itself during handling of the pin holder, but allows the pin to be released from the pin holder when held in bone. The friction fit part can include an O-ring. The O-ring can be a rubber O-ring.
The invention can also be provided as a kit of parts comprising a pin impactor according to the first aspect of the invention and at least two pins or a pin for each pin holder of the pin impactor.
The invention can also be provided as an assembly comprising a pin holder according to the first aspect of the invention and a pin located in each pin holder of the pin impactor.
According to a second aspect of the present invention, there is provided a method of pinning a surgical instrument to a bone using a multi-pin pin impactor holding at least two pins comprising: introducing a first pin held by the pin impactor into an aperture or mounting formation of the surgical instrument mounted on a bone; applying a force to the pin impactor to drive the first pin into the bone; changing the orientation and/or position of the pin impactor and introducing a second pin held by the pin impactor into a second aperture or mounting formation of the surgical instrument without re-loading the pin impactor; and applying a force to the pin impactor to drive the second pin into the bone.
Hence, there is no need to re-load the pin impactor during use. The surgeon merely re-positions and/or re-orients the pin impactor in order to allows a second pin to be driven into bone to fix instrumentation. Therefore, the number of steps is reduced, making surgery quicker, and also sharps handling is reduced making the risk of injury or glove damage less.
Similar items in different Figures share common reference numerals unless indicated otherwise.